Thinking that this is the right place to start? I have a complete stock exhaust system (heat exchangers, muffler, cat, air injection pump and piping) for a 1988 930 that I am going to sell. I am going to put it in the for sale section after I get a bit of feedback from the group that would know about what its value is? Do California cars need the stock system? Shipping will be interesting as those parts are heavy. I will get pictures together and post the system on the for sale section soon.